Multicap casing head



March '7, 1933. w. D. SHAFFER 1,900,260

MULTICAP CASING HEAD Filed June 6, 1930 INVEN TOR,

" ATTORNEY.

' Patented Mar; 7, 1933 WILLIAM D. SHAIFER,

or BREA, CALIFORNIA MULTICAP CASING HEAD Application filed June 6,

This invention relates to what is known as casing heads such as areemployed in wel drilling practice and well systems.

In such systems it is frequently the prac- .5 tice to telescope one ormore inner casing strings (of pipe).

It is desirable to cap off each casing string in a close-cut relation;to enable the capping without cutting and threading the, casing 10 topsand without application of threaded fittings; to provide a slip-deviceto grip and suspend each respective casing individually, and to providemeans for making a gas seal and which means 15 is adapted to beinstalled and replaced or reand each cap having an internal, adjustablepacking gland device accessible from its top.

The invention consists in certain advancements in thisart as set forthin the ensuing disclosure and having, with the above, additional objectsand advantages, and whose construction, combination and details ofmeans, and the manner of operation will be made manifest in thedescription of the herewith illustrative embodiment; it being understoodthat modifications, variations and adapta- 35 tions may be resorted towithin the scope,

principle and spirit of the invention as it 1s more directly claimedhereinafter.

The drawing is a partial elevation an axial section of assembled casingsand the applied head.

The present casing head comprises a sill or base collar 2 fitting theouter casing O and having an internal shoulder 3 bored to about theinner diameter of the casing 0 so that collars of an inner casing I mayfreely pass up or down. This sill collar 2 is provided with a baseflange 4 to rest on a cellar frame or other foundation.

Superimposed on the collar 2 is a cap sec- 50 tion 5 with a bottomring-bead 6 registering a simple and practicable- 1930. Serial No.459,436.

with a packing groove 6' in the top face of the collar 2 and compressinga packing 7 therein.

The cap 5 has a base flange 8 and is attached by bolts 9 therethrough tothe sill collar 2. and has a top flange 10- for attachment of a similarcap element. The body of the cap '5 has a downwardly convergent bore 5of such minor diameter as to pass coupling collars on the casing Igripped and suspended by a set of taper slips 12 setting in the cap 5and whose upper endsare provided with screw holes 13 for pulling tools(not shown). v

A gas outlet connection 14 opens through the cap 5 to the space below itand about the casing P. A feature of this cap is to provide foreffective packing against very high gas pressures sometimes encounteredin wells. As here shown the cap bore has a cylindrical upper portionthreaded to receive a follower 15 operative on an upper part or splitglandring 16 bearing on a body of deformable packing 17 supported on asplit-ring 18 resting on a ledge 5 in the bore.

The head assembly shown includes, also, inner casings I and I and eachof these is supported individually on its respective cap 5 and 5", whichare similar to cap 5, exceptin size.

The superimposed caps are fastened against lift by gangs of flange bolts9.

When the casings are to be capped off each is roughly cut across on aline just below the top of its supporting cap (55-5) so that the nextupper cap can be imposed without interference.

While each casing is severally supported by its cap the surrounding wellspace is sealed off by its respective packer set (15 17) and. this canbe effectively jammed while the adjacent follower is exposed beforeapplication of the next higher cap.

Flow from the well is provided by a crown flange 20 bolted at 21 to thetop cap 5", and having a nipple or flow pipe 22 of about the diameter ofthe innermost casing.

This multi-cap casing head is highly eflicient, of great strength, ispractical and simple, and its packing, backed up by thefol- This casingis lower, holds against high gas pressure. It will be seen that the capsdo not have a close lit on the casings but are of such bore size as tofreely pass coupling collars of the relative casing. Any inner casingcan be raised or lowered without disturbing the casings outwardlythereof. And the packer can be removed from the bore of a cap so thatthe slips can be inserted or removed while the cap is in place about thecasing.

What is claimed is:

In a concentric casing head apparatus a plurality of separable.connected, superimposed cap units, each with an internal conical bore intheir lower ends and grip slips therein to hang a respective casing.each cap bore adapted to permit passing of coupling collars of relativecasing, and each having a packer assembly disposed above the slips inthe caps and including an adjustable follower ring threaded from end toend and wholly screwed in its respective cap below the top plane ofrespective caps, the bottom of each superposed cap wholly overhangingthe packer assembly in and being substantially coplanar throughout andflush with the next lower cap; each packer being readily accessible fromthe top bore of its cap in the absence of higher caps in the apparatus.

WILLIAM D. SHAFFER.

